Recent action with a result NOW
If we don’t say the duration, (если не говорить for three weeks, since January и т.д.) we mean “recently”. Here we emphasize that the action happened in the past and it has a result NOW.

Why is the pavement wet? Because it’s been raining. – long action (raining) which is already over. But the result can be seen now – the puddles.

We can use the Present Perfect Continuous to emphasize that the action is temporary. Look at this example:She’s been reading stupid novels lately. (She usually doesn’t read such books, usually she likes non-fiction, but lately she’s been reading stupid novels)

When we want to talk about a permanent situation, we can use the Present Perfect simple tense.Jane has worked as a teacher for ten years. She is still a teacher, it’s her permanent job.

The Present Perfect Continuousfocuses on the duration of an action, how long it has been happening, while the present perfect simple focuses on completion of the action – the result.

In the first sentence, my action is over. The dining room is now painted and ready. We have a result.
In the second sentence, the action is not over, I want to show that it’s in progress, this is a process. Probably I look like this:

By the way, we can’t use the Present Perfect continuous tense with state verbs – we need to use the Present perfect simple with state verbs.

NOT : I’ve been knowing him for ten years, but I’ve known him for ten years. Know – state verb.